If a light impurity (such as horse or cow urine) covers exactly one-fifth (1/5th) of a garment sleeve, is prayer valid in that garment?

Excused Limits of Impurities and Wiping/Sprinkling Rules

• No, because any amount of horse urine invalidates prayer.
• Yes, because it is less than the excused limit of one-quarter (1/4th) of the sleeve.
• Only if washed once.
• Only for female worshippers.